Warped Carb Body

[CharlieB]

Hi all,
I have '76 Spider with the stock Weber 32 ADFA carb. Apparently I bolted the carb down too much on the manifold and the bottom of the carb body is warped. Is there a way to flatten it out, or am I now in the market for a new carb? I'll take some photos later today and post here. I just wanted to see if anyone else out there has dealt with this on their car.
Thanks
Charlie

[SteinOnkel]

The DPO did the same thing to my original carb. I tried everything and ended up buyig a new carb. I don't think this is fixable. Maybe if you take it to a machine shop?

[CharlieB]

Thanks Stein,
Yeah I think I'll begin the search for a replacement. I have a carb from a 1970 Spider, I assume it is not compatible. If I can find it I might bolt it on and see what happens.
Thanks again,
Charlie

[Nut124]

How much warp is there? Are the throttle plates moving freely? is there a vacuum leak at the base?

If the carb seems to be working OK, I would try to file out the warp carefully.

[CharlieB]

I'll take some pics later today. To answer your question, yes there is a vac leak where it's warped. I'll try to file it flat, or at least flatter than what it is.
Thanks
Charlie

[SteinOnkel]

So the issue with mine was that the main venturi would slowly drip fuel onto the primary throttle blade where it would pool and then slowly leak into the engine and mess up the idle. We threw the book at the thing and could not figure it out. Then I discovered that the carb body was way bent out of shape.

What I done did was tape a piece of sand paper onto a flat surface (think glass table), make it wet and then run the warped piece over that. In addition I installed some new gaskets. It doesn't help that the carb is made up of three pieces.

And it still did it So I thought to hell with this and used some liquid sealant (these will only seal up temporarily) and that didn't make a change either. What I suspect can happen is that the carburetor starts to leak internally, exposing something to idle at vacuum that shouldn't be. There's no fixing that, unfortunately.

I ended up buying a Weber 34ADF knockoff from China. It cost $150 shipped and it is a plug & play replacement. The jets were huge, so I replaced those and removed some internal flashing. It is hands down the best carburetor I've ever had on a car.

[CharlieB]

I took a photo on my lunch break, hopefully I remember how to post pics.

[18Fiatsandcounting]

Hi Charlie, I was thinking similar to the above suggestions to either file (sand) it flat or use multiple gaskets, but that picture shows a pretty significant amount of warping. A good auto machine shop might be able to provide advice (or fix it), but I'm guessing that if you try to bend the flange edges back to level again, they could crack.

-Bryan

[SteinOnkel]

Oooh that's where it's warped? Not sure you can do much about that.

[CharlieB]

Thanks Bryan, yeah I'll take it to a shop and see what they see but I am not optimistic.
Stein, do you remember where you bought your Chinese carb?
Thanks,
Charlie

[18Fiatsandcounting]

One option is to buy a used one for parts, such as:
https://www.ebay.com/itm/WEBER-CARBURET ... Swvddf1njy

Of course, you might end up with another warped flange, so caution is urged.

-Bryan

[SteinOnkel]

Thanks Bryan, yeah I'll take it to a shop and see what they see but I am not optimistic.
Stein, do you remember where you bought your Chinese carb?
Thanks,
Charlie

Hmm the vendor I bought it from is no longer on ebay it seems.

This one looks like it would fit though:

https://www.ebay.com/itm/Carb-fit-FIAT- ... 0290.m3507

[DieselSpider]

If you can get to tubes that are hanging down out you could get a piece of flat plate glass and stick a sheet of sandpaper to it to plane the flange. You also could try using a press to take the bulk of the bow out before working it on the sandpaper however you will be chancing cracking the casting.

[SteinOnkel]

I would also ask why the carb was taken apart in the first place. There's no point doing surgery on a dead patient.

[CharlieB]

Thanks guys,
I doubt I can sand/grind it down enough to take the bow out but I have nothing to lose at this point. I did crank it down on the bench vise overnight and that did take some of the bow out. I was going to heat it up a bit with a torch but I'm not sure if that would help or cause new problems.
Thanks for the ebay link Stein, I'll keep that in mind.
To answer your question, I sprayed carb cleaner around the base of the carb and noticed a change in rpm. So, I took the carb apart to clean it. Thats when I noticed the warpage.
Not to get too far off topic but, the carb on my car is stamped 32ADFA2 100. I have another carb in my garage that is stamped 32ADFA11 100 that I have kept in case I needed parts. To further confuse the issue,
I have another Weber stamped 32ADFA13 102.
Does anyone have a link to a website or pdf that explains the difference in these?
That has been a mystery to me for a while.
Thanks,
Charlie